GeezerVison

# Test code: ex.py
def test():
    def fib():
        start, nextn = 0, 1
        while True:
            yield start
            start, nextn = nextn, start + nextn

    gen = fib()
    for _ in range(100000):
        next(gen)

import cProfile
cProfile.run(test.__code__)

» ./python.exe ex.py
         200003 function calls in 0.188 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.017    0.017    0.188    0.188 ex.py:1(test)
   100000    0.147    0.000    0.147    0.000 ex.py:2(fib)
        1    0.000    0.000    0.188    0.188 {built-in method builtins.exec}
   100000    0.024    0.000    0.171    0.000 {built-in method builtins.next}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}

» ./python.exe ex.py                                                     
         200003 function calls in 0.185 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.016    0.016    0.185    0.185 ex.py:1(test)
   100000    0.145    0.000    0.145    0.000 ex.py:2(fib)
        1    0.000    0.000    0.185    0.185 {built-in method builtins.exec}
   100000    0.024    0.000    0.168    0.000 {built-in method builtins.next}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}

import time
def fib(n):
    if n <= 1:
        return 1
    return fib(n - 1) + fib(n - 2)
start = time.time()
# enable profiler
fib(24)
# disable profiler
print(time.time() - start)

import time
import cProfile

profiler = cProfile.Profile()

def fib(n):
    if n <= 1:
        return 1
    return fib(n - 1) + fib(n - 2)
start = time.perf_counter()
profiler.enable()
fib(30)  # 100th
profiler.disable()
print(time.perf_counter() - start)
# Old: 0.9349823750017094
# New: 0.9253051670020795
# 1% faster 

(.venv) ~/Desktop/cpython2  main ✗                                                        
» ./python.exe ex.py                                                     
0.9349823750017094
                                                                                           
(.venv) ~/Desktop/cpython2  main ✗                                                        
» ./python.exe ex.py
0.9357958749969839
                                                                                           
(.venv) ~/Desktop/cpython2  main ✗                                                        
» ./python.exe ex.py
0.9352227920026053
                                                                                           
(.venv) ~/Desktop/cpython2  main ✗                                                        
» ./python.exe ex.py
0.924946416002058
                                                                                           
(.venv) ~/Desktop/cpython2  main ✗                                                        
» ./python.exe ex.py
0.926337541997782
                                                                                           
(.venv) ~/Desktop/cpython2  main ✗                                                        
» ./python.exe ex.py
0.9347994170000311

(.venv) ~/Desktop/cpython2  issue-126220 ✗  
» ./python.exe ex.py
0.9370929580036318
                                                                                           
(.venv) ~/Desktop/cpython2  issue-126220 ✗                                                
» ./python.exe ex.py
0.9262957079990883
                                                                                           
(.venv) ~/Desktop/cpython2  issue-126220 ✗                                                
» ./python.exe ex.py
0.9328266249940498
                                                                                           
(.venv) ~/Desktop/cpython2  issue-126220 ✗                                                
» ./python.exe ex.py
0.9382220000011148
                                                                                           
(.venv) ~/Desktop/cpython2  issue-126220 ✗                                                
» ./python.exe ex.py
0.9285237919984502
                                                                                           
(.venv) ~/Desktop/cpython2  issue-126220 ✗                                                
» ./python.exe ex.py
0.9296539580027456

cherry_picker c806cd5af677c385470001efc68da38a32919196 3.12